Filter



c. B. LANCASTER FILTER Filed Aug. 27, 1928 May 20, 1930.

IN VEN TOR.

La)? tasg z' 46400710 A TTORNE Y5.

Patented May 20, 1930 NIT-Ensures PATENT OFFICE CARL :B. ANoAsTER, orALAMEDA, GALI'FQRNIA FILTER 'irp i et on fl cd'August 2?, 1928.- se ia nseal- 9- This invention relate o impro ement in fi e sand morepar iculrly 9 grav ty filters f r puri ying rinking W Q 11 j Th PiinciPal obj ofthe n ention is t mov ba t ria, ta te, c l r, doryal all ej edim nt a dot er susp nd d matter fr m na ral Wat r to ren r i h a h u f drinkingpurposes. Another object is to p ovide a fi er of thi nature, imp e in 71- ct n an Rifl v ti e in Op ra i n, uitabl for domest c purpo ess vah ees wil appea a h ripti l gre se In thf p ification and the acc mpanyingdrawings the invention is shown'iin its P es nt p e err m, but 1 d notWish to be understo d a c llfin ieit t thisf rm h cause t may be m odecli n other forms, an i s also to b unders ood that in and'by h sh msfollo ing the description t is de ire t over the int ntion n ats e erform it m yb mbodied-J of the same.

I i In he awingafigl is an l atio of a 'filt constru ed in jacco daawith th 1 imentiom 'port o s eing b 'ok naway i 1-vertical section todisclose the inter-relation of p rts Fig.- 2 s a d tai plan view lo k gat the under surface of the porousstone plate forming the bottom of thetop reservoir. ig ros e tiol of a modi e f In de a the co ructionillustra ed in the d awin in udes the top re ervo r 1 P f rab y a iglaed ja of porcela n a su table Vitr fied composit n, hav ng the p overThis es rvoi .ha ltheiinset flang j orming h internal. h u d ia 4 u 'theextcrmilishonlder a he bottom fthis I $QI QiIiSi IIILQ l Y the pla 5 ofunglazedjporcelain o any nat ral n rous mater al, of bmhthem a manyavailable, and conventionally used for the Pu p se-v f ihis. bottomrests up e shou de 4 vand s cement d at 7 to h rmencally sealits'circurnference totheinner walls Oth r obj ts "and of the r s rv rtcompe Wa c011- r i ll ed the ein t se p th ough the Pl Thusjfar the topreservoirl is conventional in generalconstruction. Such reservoirs aresubject to one great disadvantage. If they through the plate 6 willtravel along the under surface of'the stone to a low "point beforeprecipitating into the filtering media thereunder," l

One ofthe particular features ofmy invention is the correction of thisdisadvantage. This is accomplished by counter-her ing into the undersurface of the stone 6, the annular holes 8, see 2. Such stones are notset perfectly level, the seepage are usually of a softchalky' naturepresenting no great resistance to the entrance of ahollow boring toolsuitable forv boring these annular holes 8. A plate or gigispIacedthereover, guiding and spacing'the boring tool to distribute the holes 8evenlyoverthe under surface of the plate *6. This method of boring ispreferred forfthe treatment of the conventional natural stone availablein the open market. Ifthe stone-6 is for-med or molded of plasticmaterial, as may be readily clone, it can be given the form shown inFig. 3 in which dependent ernbossments (flange lo'formiag h tap" qpe asf t conical vessel 11 QQntaining statifiedfiltering media, h reinaft rmo e. f y ld ri This vessel 11 is impervious and may .be of the samematerial as the reservoir 1. It is provided in its bottom 12, with aseries of holes 13 uniformly spaced therein, through which the filteredwater precipitates into the olla 14:, the upper opening forms the flange10 for the shoulder 5 of the reservoir 1. The olla forms a base for thewhole structure.

This olla 14 is an Indian medium for cooling water. It is formed of acoarse vitrified clay through which the water permeates and accumulateson the outer surface in the form of a sweat, the evaporation of whichlowers the temperature of the olla and its contents, thus cooling thedrinking water before its consumption. The drinking water is drawn oiffrom the olla through a suitable faucet, not shown, near its bottom. Theolla should be of greater capacity than the reservoir 1 to avoidoverflowing the latter.

The filtering media within the chamber 11 is not new in composition, butto the best of my knowledge, I am the first to combine these variouselements in the statified arrangement shown.

First in this arrangement is the filtering stone 6. This removes fromthe water, sediment consisting of the coarser particles of organic orinorganic matter that may be in suspension in the water. The waterdropping through the stone 6 is precipitated on the top layer 15 withinthe vessel 11. This layer is composed of sharp, coarse quartz sand whichbecomes closely packed and aids in distributing the water evenly beforeseeping into the next layer. From the top layer 15 the water permeatesinto the stratum 16 of crushed charcoal. The efiiciency of charcoal iswell known for the removal of gases, taste, odor, including chlorine andother chemicals that may be added to the city water. It also absorbs alarge quantity of the hardness or alkalies that may be in the water.

From the charcoal, the water seeps into the massed stratum 17. This iscomposed of a pad of pure asbestos mineral fibre.

Such pads may be perfectly formed to fit the vessel 11 by wetting theasbestos fibre sufficiently to make it plastic, then squeezing the samein a proper mold to give it shape and the desired degree of density.This form of asbestos is endorsed by the highest authorities for theremoval of bacteria, stains or coloring matter, and those elusiveimpurities that may escape through the preceding strata of filteringmatter.

The compact density of this asbestos stratum backs the water up anddelays its passage through the preceding layer of charcoal, thusincreasing the duration of the chemical reactions therein. The densityof the asbestos pad further acts to mechanically retain any smallparticles of charcoal dust that would otherwise precipitate into theolla, which is one of the disadvantages of most filters using charcoal.

From the layer 17, the purified water passes into another stratum 18 offresh, sharp sand similar to the layer 15, interposed between thestratum 7 and the bottom 12 of the vessel 11. This layer of sand 18arrests any fibres of asbestos that may detach themselves from the layerabove and also prevents the asbestos mass from packing into and sealingthe top of the holes 13, thus insuring a free evenly distributed flowthrough the bottom 12 into the body of the olla.

Should this filtering matter within the chamber 11, through neglect orother causes, become clogged or impervious, I provide an overflowopening 19 through the wall thereof above the layer 15, so that anywater accumulating therein will flow directly into the olla and preventan overflow of the chamber 11 at the point 5, for obvious reasons.

I am aware that asbestos mats have been superimposed upon filteringstone such as 6 but are unsuccessful at this point because they aresubject to sliming, accumulations of silt and other impurities that soonrender them impervious to filtration. Furthermore, at this initial stagethe asbestos mat is called upon to handle impurities that it is not bestadapted to separate from the water at this point. Its greatestefficiency is in handling bacteria, odor and organic stains that may bepresent in the water, such as water impregnated with heat, sulphur, ironand other discoloring substances.

By my combination and arrangement of the various filtering media thewater is subected to each at the point where the water content is actedupon most eificiently by the particular stratum through which it may bethen passing. this new mode of operation is that the water is morerapidly filtered and the various filtermg media are not subject toclogging by substances that they are not adapted to separate from thewater.

Having thus described this invention what I claim and desire to secureby Letters Patent is:

1. A filter comprising a reservoir with a porous bottom havingsubstantially vertical drip forming surfaces in its under side portlon;a chamber beneath said reservoir havlng a perforated bottom andsuperimposed strata of sand, charcoal, asbestos, and sand arrangedtherein in the order named.

2. A filter comprising a porous horizontal plate, said plate having uponthe under side thereof a series of shallow circular grooves to lnsuredischarge of the filtered liquid from a plurality of points throughoutthe area of said filter.

3. A filter comprising a reservoir, a porous bottom upon said reservoir,grooves upon the under side of said bottom for securing dis- Theparticular advantage of charge of the filtered water therefromthroughout the entire area thereof, a chamber to receive said water tofurther filter the same having a perforated bottom, a layer of asbestosfibre in said chamber and a layer of sand between said perforated bottomof'said chamber and said asbestos fibre to prevent said fibre fromclogging said perforated chamber bottom.

In testimony whereof I have hereunto affixed my signature.

CARL B. LANCASTER.

